#return 要返回的数据
# #函数定义
# def add (a ,b):
#      result = a+b     #  计算的和
#      return result
#
#
# result =add (4,1)
# print (result)


#实例 求2个数的和
def sum (a,b):
     print(a +b)
     return a+b

sum(2,3)  #5
sum(1,5)+sum(4,2)  #6.6